This invention relates generally to user interfaces to computational devices, and more particularly to applications in which displayed objects are selected and arranged in document images.
Two types of interactive drawing/sketching/editing applications are currently in use, both of which support creation of new image material, through draw operations, and selection and manipulation of existing material, through editing operations. The types of interactive applications are distinguished by the emphasis placed on “sketch” and “editing” operations. In an image “editing” program, selection and manipulation of image objects is the primary activity. Therefore, stylus or mouse interaction is designed primarily to interpret stylus input as selection gestures, and the default interpretation of mouse or stylus activity is selection of existing image objects for manipulation. Tools for drawing objects are provided by auxiliary command objects, usually menus.
In a “sketch” program, however, the primary activity is the “draw” operation. To facilitate the sketching process, it is important for users to be able to quickly execute a series of markings such as handwritten or sketched strokes, without having to perform a menu initiation command at every stroke. These programs are designed such that draw operations can be the default interpretation of mouse or stylus activity. The disadvantage to this type of program is that when priority is placed on draw operations, selection operations become demoted and require explicit menu choices or button clicks to invoke a selection, which impedes the smooth flow of multiple selection and manipulation operations.
In both types of interactive applications, it can be very difficult to select and move, delete, or otherwise modify salient collections of markings at will. In particular, users are sometimes imprecise in the ways that they draw encircling gestures to select image objects for further manipulation. They may unintentionally clip off a piece of an image object they intend to select. At other times, they may actually intend to split off the very same piece of this image object. One of the major drawbacks to existing graphical editors is their inability to interpret selection gestures in light of precomputed perceptual objects, so that imprecise gestures may be interpreted to either deliver the literal objects defined by the gesture, or the perceptually significant objects identified in the precomputation stage.
U.S. Pat. No. 5,485,565 to Saund et al. titled “Gestural Indicators for Selecting Graphic Objects” discloses a graphical imaging system, in which the rough location, size and shape of objects in the image is summarized by a first characteristic descriptor, representing a parametric “pose” computed for each object. A second characteristic descriptor, for example a “gesture matching” function, is provided in order to select the single object, or the set of objects, that best comports with the user's selection gesture. When most closely matched, these key characteristic descriptors permit simple and natural user gestures to distinguish among a large set of graphic objects that may overlap both spatially. User gestures can be simple slashes passing through the object, or quick, coarse approximations of objects' shapes.
U.S. Pat. No. 5,513,309 to Meier et al. titled “Graphic Editor User Interface for a Pointer-Based Computer System” discloses a graphical editor arranged to permit the user to edit selected graphic objects by highlighting the objects and moving them with editing handles. A bounding box is also drawn about the selected portions of the object. In various aspects of the invention, the user is permitted to edit the object by executing specific actions, including resizing, duplicating, distorting and moving either the entire object or only selected portions. After any of the editing operations is performed, the display is updated to reflect changes made during the editing step.
U.S. Pat. No. 5,760,773 to Berman et al. titled “Methods and Apparatus for Interacting with Data Objects Using Action Handles” teaches a central processing unit coupled to a pointer control device such as a pen, stylus or mouse, that permits the user to selectively position a pointer and activate an action handle on a display associated with a data object. Activation of the action handle signals the central processing unit of selections associated with the data object. Tapping or clicking on the action handle causes display of a context menu containing at least one command that may be invoked with respect to the data object. Dragging the action handle indicates movement or dragging of the action handle and the corresponding data object for an operation associated with dragging such as drag-and-drop.
The present invention offers a new tool for computer assisted drawing, one that provides users with the ability to make imprecise selection gestures while the application applies certain rules and image analysis operations to infer the user's intent.